Trace element concentration reduction by beneficiation of Witbank Coalfield no. 4 Seam

South Africa remains the 5th largest producer and joint 4th largest exporter of coal in the world. It is also a major supplier of coal to the European Union. This is significant as the European Union has recently supported the environmental lobby that threatens the combined full scale use of coal in Europe and other first world countries. This promotes the development of clean coal technologies in order to counter the ever increasing number of environmental constraints threatening the export market. One critical development in clean coal technologies is coal beneficiation, which allows the reduction of mineral content. Permian coals from South Africa have characteristically high ash and inertinite contents and therefore require further beneficiation. The no. 4 Seam in the Witbank Coalfield is no exception, and it can be described as containing higher inertinite content and minerals compared to the no. 2 Seam in the same Coalfield. Beneficiation, therefore, is an important requirement for improving the quality of the coal, especially for export purposes.With the increase in environmental legislation and the drive towards “clean coal” a concern is raised in terms of the performance and marketability of export coal produced from the no. 4 Seam in the Witbank Coalfield. This seam is economically significant and remains an important source of export steam coal.Due to the nature and composition of the no. 4 Seam, coal beneficiation is essential to reduce the mineral content to be in line with export quality specification levels. This paper focuses on the association of the trace elements within the seam with the organic and inorganic components and possible methods of trace element reduction by removal using coal beneficiation techniques. The techniques investigated include reduction by dense medium beneficiation and flotation. The associated mineral reducibility investigations included mineralogical distribution and liberation analysis. By studying the relationship between coal mineralogy, petrography and trace element distribution, methods of optimum trace element reduction established. Furthermore, the distribution of mineralogical and organic components of sulphur in the Witbank Coalfield No. 4 seam was found to bear unique relationships with trace elements of special concern. By assessing the distribution and occurrence of trace element concentrations during washability and floatability tests, data was produced which could now be used in the promotion of saleable coal products from no. 4 seam in the Witbank Coalfield.